#include "apue.h"

int main() {
	FILE *fp = fopen("m.mp3", "r+");
	int re;
	int flag = 0;
	while ((re = getc(fp)) != EOF) {
		flag = (flag + 1) % 2;
		if (flag == 0)
			ungetc(re, fp);
	}
	printf("over.\n");
	return 0;
}
